Genomic imprinting

The phenomenon of parent-of-origin gene expression. The expression of a gene depends upon the parent who passed on the gene. For instance, two different disorders – Prader-Willi syndrome and Angelman syndrome — are due to deletion of the same part of chromosome 15. When the deletion involves the chromosome 15 that came from the father, the child has Prader-Willi syndrome, but when the deletion involves the chromosome 15 that came from the mother, the child has Angelman syndrome. Genomic imprinting plays a critical role in fetal growth and development. Imprinting is regulated by DNA methylation and chromatin structure.

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genomic imprinting n genetic alteration of a gene or its expression that is inferred to take place from the observation that certain genes are expressed differently depending on whether they are inherited from the paternal or maternal parent called also genetic imprinting, imprinting

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differential expression of a gene or genes as a function of inheritance from the male versus the female parent, e.g., a deletion on chromosome 15 that causes Prader-Willi syndrome if inherited from the father causes instead Angelman syndrome if inherited from the mother. Imprinting appears to be controlled by DNA methylation patterns that are not erased during gametogenesis.